Line an 8-inch square pan with waxed paper, making sure there is overhang for easy removal; set aside.
Add the creamy peanut butter and jar of cream cheese frosting into a microwave-safe bowl. Heat the mixture in the microwave on high for 30 seconds. Stir mixture and heat for an additional 30 seconds. Stir until smooth and thoroughly blended.
Working quickly, pour the fudge mixture into the prepared baking pan. Refrigerate until chilled, about 1 hour. Remove fudge from the pan using the waxed paper overhang. Cut into 1” squares.
Notes
This recipe was tested with Jif brand creamy peanut butter and Duncan Hines whipped cream cheese frosting.
Use a small offset spatula to smooth the peanut butter into the pan. Dip the spatula in hot water for even smoother results.
Cut the fudge with a sharp knife. Be sure to wipe the knife carefully with a damp towel in between cuts to keep the pieces of fudge nice and clean.